Improvement in apparatus for evaporating sugar-juice



A. JOUAN.

Eva parating Pan.

No. 22,732 Patented .lan'y 25, 1859.

UNITED STATES ATENT OFFICE.

AUGUSTUS JOUAN, OF SAN FRANUISO, CALIFORNIA.

Specilication forming part of Letters Patent No. 22,732, dated January 25, 1"59.

To all whom it may concern Be it known that I, AUoUs'rUs JoUAN, of San Francisco, in the State of California, have invented a new and useful Floating Cover Apparatus for Cooking Sugar; and I do hereby declare the following to bc a full and exact description thereof, reference being had to the acconpanying drawings, and to the letters and marks thercon.

Of the drawings forming part of this specification, Figure 1 is a perspective view of the cover and means for guiding it, Fig. 2 being a Sectional view of the cover and pan.

My invention consists in the addition of a floating cover to the ordinary sugar-pan. The cover a is made of metal. It is hollow, of a eonvexoconcave forn, as shown by the drawings, of a weight so as to float in saceharinc liqids, and with an arrangement allowing it to be inore or less inmerged, as circumstances may require. It is composed of two parts, one of which, b, is convex and the other, r, concave. The convex,which forms the upper part of tle cover, is scni-spherical, wlile the concave part represents the form of a funnel. ln the centerof each part isahole, d, to which is attached a distinct tube, there being thus two tubes running parallel. The exterior tube, c, is slightly conical from about two inches before its junction with the other tube. At about two inches above its base the external tube, c, has an opening, o, which is very small, designed only for the purpose of allowing the air in the cover to expand when it has become leated. This opening o is partly covered, so as not to adnit the sirup ejected by the tubo to enter into the cavity of the cover. The base of the cover f is eircular; it may be of any other form, to suit that of the pan. lt must be adjusted to the pan g, but not so as to close hermetically, as the liquid,whcu eject ed fron the tube, must return under the cover, passing lthrough the slight space between the cover and the sides of the pan. In length the tubes e Z should be about two thirds the diameter of the pan, and their diameter be in proportion to said diameter as one inch is to a foot. A novable sieve ean be adapted to the tube, as shown at h` on the drawings. Above this sieve there can be placed another one; but the one shown is specially for dctaining the grosscr parts and impurities of the liquid at the beginning of the operation. Tle sieve h has a handle, so lhat it can be taken off the tube whenever desirable.

To govern the cover and to plunge it more or less downward and maintain it in position, a collar, i, is used, which passes over the center of the pan and is attached to the sides of the pan. lt has an arrangement of screwrodsj connected to it, for the purpose of forcing and holding the cover below the line at which ils buoyancy would sustain it.

.ilfoluaopcruul: The liquid in the pan should have added to it the necessary ingredienls for cleaning it, and should be slirred as in lbc usual or ordinary mode. Then the cover is placed in its position, and a moderate fire is maintained till after the first eruption of the liquid through the tube. From that moment the heat is increased to any degree required till the sirup las acquired about 300 llanmeis hydrometer. Then again the fire is moderated, not to injure the process of crystallization, and it is maintained with moderate heat till the end of the opera Lion. At the beginning of the operation the cover is only compressed to such a degree as to make it steady; but wlen the sirup has be come condensed to the degree named above, and the ire is made moderate, the cover must be compressed into the sirup until the main body of the cover is entirely imnerged, and so it must remain until the sirup is cooked. During the operation the degree of conder salion of the sirup can be tested by plunging an iron rod into it through the tube c; but a small allowance must be made to compensate the dill'ercnce of condcnsation between the sirup near the bottom of the pan and that which is floating over the cover and has a lower degree of concentration.

This apparatus has the advantages of causing an extraordinary direct evaiioration and of aiding the filtering operation, and, above all, it has that of coucentrating the sirup to the degree of perfect crystallization under a comparatively low temperature, operating in that respcctsimilar tothe vacuum-pan. Crystallization is made perfect and the operation is performed with a great economy of fuel, time, and labor, and a very small quantity of 

